JPS6230754A - Novel triphenyl compound - Google Patents

Abstract

NEW MATERIAL:1-(p-Methylbenzyloxy)-4-benzylmercaptobenzene of formula. USE:An agent for improving sensitivity of a recording material. A heat-sensitive recording material having improved sensitivity, high whiteness of the unexposed part, excellent storage stability and extremely high practicality and suitable for high-speed recording can be produced by using the compound of the present invention. PREPARATION:The compound of formula can be produced easily, in high yield and purity at a relatively low cost, by reacting a monothiohydroquinone with a benzyl halide under alkaline condition and reacting the product with a halogenated xylene under the same condition. A heat-sensitive recording material can be produced from the compound by bonding the triphenyl compound of the present invention together with a leuco dye, a color developer and an assistant component to a supporting substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a compound useful as a sensitivity improver in a heat-sensitive recording material that utilizes a color-forming reaction between a leuco dye and its color developer.

[Prior art]

General heat-sensitive recording materials are coated on a support such as paper or film, and contain a colorless or light-colored dye such as a leuco dye as a color former, and a phenolic compound (particularly bisphenol A) as a color developer to make the color develop when heated. A heat-sensitive color-forming layer in which a binder, filler, sensitivity improver, lubricant, and other auxiliary agents are further dispersed in a color-forming system consisting of an acidic substance such as an organic acid. Kosho 45-14
No. 039 and Japanese Patent Application Laid-Open No. 48-27736, it has been widely put into practical use. This type of thermal recording sheet produces a colored image through an instantaneous chemical reaction between a coloring agent and a color developer during heating (a thermal printer or facsimile machine with a built-in thermal head is used for heating). because there is,
Compared to other recording materials, records can be obtained in a short time using relatively simple equipment without complicated processing such as development and fixing, there is less noise generation and environmental pollution, and the cost is low. Due to the advantages of
It is useful as a recording material for various information and measuring instruments such as medical measuring instruments.

On the other hand, in recent years, along with the development of society, there has been an increasing demand for higher speed and higher density recording. For this reason, there is a strong desire not only to increase the speed of the recording apparatus itself, but also to develop recording materials that can handle this. The first method is to lower the melting point of the electron-accepting metal used as a color developer to a practically acceptable level (for example, 80 to 120°C), and then combine it with the melting start temperature of the leuco dye. The objective is to reduce the speed and speed up the process. However, it is difficult to control the melting point of phenolic compounds, which are color developers that are currently widely used in the field of heat-sensitive recording materials.

As for the second method, in which the phenolic compound itself is expensive and has poor practicality, for example, Japanese Patent Application Laid-Open No. 53-3913
No. 9, JP-A-53-26139, JP-A-53-563
No. 6, JP-A No. 53-11036, etc., the heat-sensitive coloring layer contains various waxes, fatty acid amides, alkylated biphenyls, substituted biphenylalkanes, coumarins, diphenylamines, etc. with low melting points. There is a method of adding a melting substance as a sensitizer (or melting point depressant). However, the heat-sensitive recording materials produced based on these methods are still not sufficient in terms of color density, color sensitivity, background whiteness, etc.

〔the purpose〕

An object of the present invention is to provide a novel compound that has a sufficient color density of 5 color layers, is suitable for high-speed recording, and is extremely practical as a sensitivity improver for heat-sensitive recording materials with high background whiteness. .

〔composition〕

As a result of various studies aimed at achieving the above object, the present inventors discovered that the triphenyl compound represented by the formula is suitable for the object, and completed the present invention.

The triphenyl compound represented by the above formula of the present invention can be easily produced in high yield and by reacting monothiohydroquinone with a halogenated benzyl under alkaline conditions and further reacting a halogenated xylene under the same conditions. It can be synthesized with high purity and at relatively low cost.

The triphenyl compound of the present invention can be used as an excellent sensitivity improver for heat sensitivity and high-speed recording, and furthermore, the heat-sensitive recording material obtained using the same has excellent stability in the background area and colored area and high speed recording. It also has excellent color development. In addition, heat-sensitive recording materials using low melting point substances such as various waxes, fatty acid amides, alkylated biphenyls, substituted biphenylalkanes, coumarins, and diphenylamines, which are conventionally known as sensitizers (or melting point depressants).

Although it is difficult to say that it is sufficient in terms of color density 1 color development sensitivity, background whiteness, etc., the triphenyl compound of the present invention is an extremely excellent sensitivity enhancer that does not have such drawbacks. can.

When producing a heat-sensitive recording material using the triphenyl compound of the present invention as a sensitivity improver, the triphenyl compound of the present invention may be used in combination with a coloring system consisting of a conventionally known leuco dye and a color developer. The leuco dyes may be applied alone or in a mixture of two or more types. As such leuco dyes, those applied to this type of heat-sensitive material can be arbitrarily applied, such as triphenylmethane-based, Leuco compounds of dyes such as fluoran-based, phenothiazine-based, auramine-based, spiropyran-based, and indolinophthalide-based dyes are preferably used. Specific examples of such leuco dyes include those shown below.

3.3-bis(ρ-dimethylaminophenyl)-phthalide, 3.3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone), 3.3-bis(p- dimethylaminophenyl)-6-dibutylaminophenyl, 3.3-bis(p-dimethylaminophenyl)-6-chlorphthalide, 3.3-bis(P-dibutylaminophenyl)phthalide, 3-cyclohexylamino-6-chlor Fluoran, 3-dimethylamino-5,7-dimethylfluoran.

3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6-methyl-7-chlorofluorane, 3-(N -p-tolyl-N-dithylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2-(N-(3'-trifluoromethylphenyl) )
amino)-6-dinithylaminofluorane.

2-(3,6-bis(diethylamino)-9-(o-
chloranilino)xantylbenzoic acid lactam), 3-
Diethylamino-6-methyl-7-(m-trichloromethylanilino)fluoran.

3-diethylamino-7-(0-chloroanilino)fluoran, 3-dibutylamino-7-(0-chloroanilino)fluoran, 3-N-methyl-N-amylamino-6-methyl-7-
Anilinofluorane.

3-N-methyl-N-cyclohexylamino-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane, 3-(N,N-diethylamino)-5- Methyl-7-(
N.

N-dibenzylamino)fluoran, benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-pyrylosbilane.

6'-Bromo-3'-methoxy-benzoindolino-pyrylospirane, 3-(2'-hydroxy-4'-dimethylaminophenyl)-3-(2'-methoxy-5'-chlorophenyl)phthalide, 3- (2'-hydroxy-4'-dimethylaminophenyl)-3-(2'-methoxy-5'-nitrophenyl)phthalide, 3-(2'-hydroxy-4'-diethylaminophenyl)-3-(2 '-methoxy-5'-methylphenyl)phthalide, 3-(2'-methoxy-4'-dimethylaminophenyl)-3-(2'-hydroxy-4'-chloro-5'
-methylphenyl)phthalide, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluorane, 3-diethylamino-5-chloro-7-( N-benzyl-trifluoromethylanilino)fluoran, 3-pyrrolidino-7-(di-p-chlorophenyl)methylaminofluoran, 3-diethylamino-5-chloro-7-(α-phenylethylamino)fluoran, 3-(N-ethyl-P-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(o-methoxycarbonylphenylamino)fluoran, 3-diethylamino-5-methyl-7-( α-phenylethylamino)fluorane, 3-diethylamino-7-piperidinofluorane, 2-
Chloro-3-(N-methyltoluidino)-7-(ρ-n
-butylanilino)fluorane.

3-(N-benzyl-N-cyclohexylamino)-5
, 6-penzo7-α-naphthylamino-4'-bromofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-N-ethyl-N-(2-ethoxypropyl)amino-6 -Methyl-7-anilinofluorane, 3-N-ethyl-N-tetrahydrofurfurylamino-6-methyl-
7-anilinofluorane.

3-diethylamino-6-methyl-7-mesitidino 4
', 5'-benzofluorane, etc.

Further, as the color developer, various electron-accepting compounds 1 such as phenolic compounds, thiophenolic compounds, thiourea derivatives, organic acids and metal salts thereof are preferably used, and specific examples thereof are shown below. show.

4.4'-isopropylidene bisphenol, 4.4
′ -isopropylidene bis(O-methylphenol)
, 4.4'-Secondary-butylidene bisphenol,
4.4'-isopropylidene bis(2-tertiary-
butylphenol), 4,4'-cyclohexylidene diphenol, 4.4
′ -isopropylidene bis(2-chlorophenol)
.

2.2'-methylenebis(4-methyl-6-tert-butylphenol), 2.2'-methylenebis(4-ethyl-6-tert-butylphenol), 4.4'-butylidenebis(6-t, ert, butyl -2-methyl)phenol, 4.4'-thiobis(6-tertbutyl-2-methyl)phenol.

4.4'-diphenol sulfone, 4.4'-diphenol sulfoxide, isopropyl P-hydroxybenzoate, benzyl P-hydroxybenzoate, benzyl protocatechuate, stearyl gallate, lauryl gallate, octyl gallate, 1. 7-bis(4-hydroxyphenylthio)-3,5
-dioxahebutane, 1,5-bis(4-hydroxyphenylthio)-3-oxapentane.

1.3-bis(4-hydroxyphenylthio)-propane, 1.3-bis(4-hydroxyphenylthio)-2-hydroxypropane, N,N'-diphenylthiourea, N,N'-di(a+ -chlorophenyl)thiourea, salicylanilide.

5-chloro-salicylanilide, 2-Hydroxy-3-naphthoic acid.

2-Hydroxy-1-naphthoic acid.

■-Hydroxy-2-naphthoic acid, metal salts of hydroxynaphthoic acid such as zinc, aluminum, calcium, etc.

In order to produce a heat-sensitive recording material using the triphenyl compound of the present invention, the triphenyl compound of the present invention, the leuco dye, the color developer, and the auxiliary components may be bonded and supported on a support. As the binder, various commonly used binders can be used as appropriate, such as polyvinyl alcohol, starch and its derivatives, methoxycellulose,
Cellulose derivatives such as hydroxyethylcellulose, carboxymethylcellulose, methylcellulose, and ethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, acrylic amide/acrylic ester copolymer, acrylic amide/acrylic ester/methacrylic acid ternary copolymer, styrene Water-soluble polymers such as / maleic anhydride copolymer alkali salt, isobutylene / maleic anhydride copolymer alkali salt, polyacrylamide, sodium alginate, gelatin, casein, polyvinyl acetate, polyurethane, styrene-butadiene copolymer Coalescence, polyacrylic acid, polyacrylic ester.

Latexes such as vinyl chloride/vinyl acetate copolymer, polybutyl methacrylate, ethylene/vinyl acetate copolymer, styrene/butadiene/acrylic copolymer, etc. can be used.

In addition, when obtaining a heat-sensitive recording material according to the present invention, together with the triphenyl compound, the leuco dye and the color developer,
If necessary, auxiliary additive components commonly used in this type of heat-sensitive recording material, such as fillers, surfactants, thermofusible substances (or lubricants), etc., can be used in combination. In this case, examples of fillers include calcium carbonate, silica, zinc oxide,
Titanium oxide, aluminum hydroxide, zinc hydroxide, barium sulfate.

Examples include inorganic fine powders such as clay, talc, and surface-treated calcium and silica, as well as organic fine powders such as urea-formalin resin, styrene/methacrylic acid copolymer, and polystyrene resin.

In the heat-sensitive recording material using the triphenyl compound of the present invention, the amounts of the leuco dye, the color developer, and the triphenyl compound of the above formula are 5 to 40% by weight, 20 to 60% by weight, and 20 to 60% by weight, respectively. is appropriate.

〔effect〕

The heat-sensitive recording material using the triphenyl compound of the present invention as a sensitivity enhancer has improved sensitivity and is therefore suitable for high-speed recording, has high background whiteness, has excellent storage stability, and is extremely practical. It is.

〔Example〕

Examples of the present invention are shown below. Note that parts and percentages shown below are parts by weight and percentages by weight, respectively.

Example 1 Dissolve 49.8 g of sodium hydroxide in 250 g of methanol, and dissolve 157.0 g of P-hydroxybenzenethiol.
Add. Benzyl chloride 15 was then added to this mixture.
0. Q was added dropwise at room temperature, and after the addition was completed, the mixture was heated and reacted under methanol reflux conditions for 3 hours. After the heating reaction is completed, cool the
After methanol was distilled off under reduced pressure, 2Q of water was added to the residue, and the precipitated crystals were filtered and thoroughly washed with water. After drying, it was recrystallized with a toluene solvent to obtain 230 g of a white product of 4-benzylmercaptophenol. Furthermore, 4-
24.3 g of benzylmercaptophenol are added to a solution of 4.5 g of sodium hydroxide in 80 g of methanol. Next, 15.0 g of α-chloro-P-xylene was added dropwise to this mixture at room temperature, and after the addition was completed, the reaction was heated under methanol reflux conditions for 1 hour. After the heating reaction was completed, the mixture was cooled, and the precipitated crystals were collected by filtration and thoroughly washed with methanol and water. After drying, with a mixed solvent of hexane-toluene,
Recrystallize to give 1-(p-methylbenzyloxy)-4-
16.5 g of white crystals of benzylmercaptobenzene were obtained. Melting point 92-93°C.

Elemental analysis results Carbon Hydrogen Sulfur Theoretical value 78.71% 6.29% 10.00% Synthetic product 78.42% 6.17% 9.95% Application example 1 Each of the following mixtures was ground in a magnetic ball mill for 2 days. A liquid, a liquid B, and a liquid C were prepared by dispersing.

[Liquid A prescription]

3-(N-methyl-N-cyclohexylamino)-6-
Methyl-7-anirite fluorane
20 parts 10% aqueous solution of hydroxyethylcellulose 20 parts water
6
0 parts [Liquid B formulation] Bisphenol A 20 parts 10% aqueous solution of hydroxyethyl cellulose 20 parts Water
60
[Liquid C prescription] 1-(p-methylbenzyloxy)-4-benzylmercaptobenzene (melting point 92-93°C) 20 parts 5% aqueous solution of methylcellulose 20 parts Water
60
[Liquid D prescription] Calcium carbonate 20 parts Methyl cellulose 5% aqueous solution 20 parts Water
607/Next, 10 parts of liquid A, 30 parts of liquid B, 30 parts of liquid C, 20 parts of liquid D, and 10 parts of a 20% alkaline aqueous solution of isobutylene-maleic anhydride copolymer are mixed to prepare a thermosensitive coloring layer forming liquid, The basis weight of this is 50g/rr? Dry coverage on high quality paper is 4.
A heat-sensitive coloring layer was provided by coating and drying to give a coating thickness of ~5 g/=, and then the layer surface was calendered to give a surface smoothness of SOO to ~600 seconds to prepare a heat-sensitive recording material (a).

Application example 2 Heat-sensitive recording material (b) was prepared in the same manner as application example 1 except that the following liquid (E) was used instead of liquid (B) in application example 1.
It was created.

[E liquid prescription]

20 parts of p-hydroxybenzoic acid benzyl ester 10% aqueous solution of hydroxyethyl cellulose 20 parts water
60
〃Application Example 3 Heat-sensitive recording material (c) was prepared in the same manner as in Application Example 1 except that the following CF) liquid was used instead of the [B) liquid in Application Example 1.
It was created.

CF liquid formulation] 1.7-bis(4-hydroxyphenylthio)-3,5
-Dioxahebutane 20 parts 10% aqueous solution of hydroxyethylcellulose 20 parts water
6
0 parts Comparative Example 1 Application Example 1 except that water was used instead of liquid [c] in Application Example 1.
A thermosensitive recording material (d) was prepared in the same manner as above.

Comparative Example 2 A heat-sensitive recording material (,) was prepared in the same manner as in Application Example 2 except that water was used instead of liquid [c] in Application Example 2.

Comparative Example 3 A heat-sensitive recording material (f) was prepared in the same manner as in Application Example 3 except that water was used instead of liquid (C) in Application Example 3.

Comparative Example 4 A heat-sensitive recording material (g) was prepared in the same manner as in Application Example 1, except that the following liquid (G) was used instead of liquid (c) in Application Example 1.

[G liquid prescription]

Stearic acid amide 20 parts 5% aqueous solution of methylcellulose 20 parts water
60 Comparative Example 5 A heat-sensitive recording material (h) was prepared in the same manner as in Application Example 2 except that the liquid CG) was used instead of the liquid (C) in Application Example 2.

Comparative Example 6 A heat-sensitive recording material (i) was obtained in the same manner as in Application Example 3, except that the liquid CG) was used instead of liquid [c] in Application Example 3.

The heat-sensitive recording materials (a) to (i) obtained as described above are
Dropping electronic components (using a thermal printing experimental device with a thin film head made of Il, head power 0.45 sp/dot, 1 line recording time 20 m5 ec/Q, scanning line density 8 x 3.85 dot/mm, pulse width 1. 6.2.0.2.4(
msec), and the print density is measured using Macbeth Densitometer R.
Measured with D-514 (filter W-106). The results are shown in Table-1.

Table 1 Next, heat-sensitive recording materials (a) to (i) were subjected to a 24-hour storage test under dry conditions at 60° C., and changes in skin density were examined. The results are shown in Table-2.

Table 2 As is clear from Tables 1 and 2, the heat-sensitive recording material formed using the triphenyl compound of the present invention as a sensitivity improver has excellent color development during high-speed recording, and has excellent storage stability in the background area. It can be seen that it is an extremely excellent heat-sensitive recording material.

Claims (1)

[Claims] (1) Formula ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ A triphenyl compound represented by